U1922 – Module Communication Failure

The ODBII code U1922 indicates a “Module Communication Failure,” meaning there is a problem with communication between vehicle modules, often due to a fault in wiring, connectors, or the modules themselves.

The severity of ODBII code U1922 is moderate.

Common Causes For: U1921 U1921: Body Control Module Communication Error

• Faulty wiring or connectors
• Failed or malfunctioning control module
• Poor ground connections
• Corroded or damaged pins in connectors
• Intermittent communication issues
• Software or firmware issues in modules
• Low battery voltage or power supply issues
• Electrical interference or noise
• Faulty CAN bus communication
• Incompatible or missing modules

Common misdiagnosis for U1922 U1922: “Module Communication Failure”

• Faulty wiring or connectors
• Defective control module
• Software issues or updates needed
• Power supply problems
• Grounding issues
• Intermittent communication issues
• Other module failures (e.g., ABS, BCM)
• Corrupted data or configuration errors

Common Troubleshooting Steps

The OBD-II code U1922 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between the vehicle’s control modules. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Other Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected module(s). Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the ground connections, as poor grounding can lead to communication issues.
• Check Power Supply:
• Ensure that the affected module is receiving the proper voltage and ground. Use a multimeter to check the power supply to the module.
• If the module is not receiving power, trace the wiring back to the fuse box and check for blown fuses or damaged wires.
• Test the Module:
• If possible, test the affected module by swapping it with a known good module (if applicable) to see if the problem persists.
• Some modules may have self-diagnostic capabilities that can provide additional information.
• Inspect the CAN Bus:
• If the vehicle uses a Controller Area Network (CAN) bus for communication, check the integrity of the CAN bus wiring. Look for shorts, opens, or interference.
• Use an oscilloscope to check the CAN bus signals if you have access to one. The signals should have a specific voltage level and waveform.
• Check for Software Updates:
• Sometimes, communication issues can be resolved with a software update. Check with the vehicle manufacturer or a dealership to see if there are any updates available for the affected module(s).
• Clear Codes and Test Drive:
• After performing any repairs or inspections, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs):
• Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued bulletins regarding known communication issues and their fixes.
• Professional Diagnosis:
• If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized diagnostic tools and experience with the specific vehicle. By following these steps, you should be able to identify and resolve the underlying cause of the U1922 code.